Generally when using tape dispensers, a coating composition to be laid down onto a substrate surface is supplied on a carrier ribbon. During use of the dispenser, the correction tape is transferred onto the substrate surface as a continuous strip while the carrier ribbon is retained by the dispenser.
Hand-held devices for applying a film or a correction tape on a surface (alternately referenced herein as a tape dispenser for the sake of convenience without any intent to limit) typically comprise separate supply and take-up reels provided within a casing of a dispenser, and the two reels are linked by a drive mechanism as well as a clutch mechanism. Due to the size of the reels, considerable space is required within the casing of the dispenser. This is in contrast to the general trend towards slim elongated pen-shaped dispensers.
A tape dispenser as shown in FIGS. 11 and 12 is known from WO 97/12827. According to this known dispenser, the ends of the carrier ribbon are spliced together so that the ribbon is a continuous loop and the tape is wound in several super-imposed layers around the pair of spaced equal-diameter reel members thereby forming an oval reel of tape. The oval reel is accommodated in an elongate casing of general slim configuration. A section of tape between the inner and outermost windings of the reels is arranged to extend out of the casing and over an applicator head or tip which is used to press the tape against the substrate surface when using the dispenser. Two reel members are respectively carried for independent rotation about their respective axes. When the tape is pressed against the substrate surface by means of the tip edge and the tip is moved over the surface in a direction substantially perpendicular to the edge, the correction tape is transferred to the surface from the carrier ribbon and is laid down as a continuous strip. Fresh tape is drawn from the supply reel and is drawn from the innermost winding of the reel at the rearmost reel. To assist the separation of the tape from the reel, the reel is preferably given a profile so that it displaces the innermost winding out of the plane of the reel. The separated tape passes over the forwardmost reel and to guide rollers before traveling onto the applicator head. As the tape is delivered from the innermost winding of the oval reel, the outer layers move inwardly and some slippage occurs between the adjacent layers. The friction between the slipping layers can be used to ensure the tension needed in the tape to control the portion extending around the applicator head.
The known reel arrangement as shown in FIGS. 11 and 12 has an advantage because the amount of tape held in the oval reel is substantially greater than would be stored in the same number of layers around a single cylindrical reel. However, this oval reel arrangement inherently has the disadvantage that the different layers on the reel are increasingly squeezed together onto each other when using the dispenser. This is due to the fact that a certain rewound length of tape is always fed back on a diameter which is substantially larger than the diameter from which fresh tape is drawn to the applicator head. Due to the squeezing effect, the different layers wound on the reel are wound tighter and tighter on the reel. The thus resulting friction between the layers is substantially increased, and once the friction has exceeded a certain limit, it is no longer possible to use the dispenser without breaking the tape.
In the tape dispenser described in DE 40 39 683, the manual device has a casing with an elongated shape and the supply reel is pressed together into an elongated shape and the backing tape is drawn back into a space within the casing.
A design similar to the design described above is provided in a tape dispenser according to DE 42 17 294. In this known dispenser, the supply reel is pressed together into an elongated shape and the backing tape is wound up onto a take-up reel placed behind the supply reel.
In view of the above prior art, it would be desirable to provide a dispenser for applying a tape on a substrate surface, wherein the dimensions of the casing of the dispenser should be reduced to an elongated shape without encountering the problems known from WO 97/12827.